Next Article in Journal
Modernization and Optimization of Phosphoric Cast Iron Casting
Previous Article in Journal
An Introduction to Wear Degradation Mechanisms of Surface-Protected Metallic Components
Previous Article in Special Issue
Structural Aspects of Execution and Thermal Treatment of Welded Joints of Hardox Extreme Steel
Open AccessArticle

Internal Material Flow Layers in AA6082-T6 Butt-Joints during Bobbin Friction Stir Welding

1
University of Canterbury, Department of Mechanical Engineering, Christchurch 8140, New Zealand
2
Fakulti Kejuruteraan Pembuatan, Universiti Teknikal Malaysia Melaka, Durian Tunggal 76100, Malaysia
*
Author to whom correspondence should be addressed.
Metals 2019, 9(10), 1059; https://doi.org/10.3390/met9101059
Received: 9 August 2019 / Revised: 26 September 2019 / Accepted: 26 September 2019 / Published: 28 September 2019
(This article belongs to the Special Issue Characterization of Welded Joints)
Bobbin friction stir welding with a double-sided tool configuration produces a symmetrical solid-state joint. However, control of the process parameters to achieve defect-free welds is difficult. The internal flow features of the AA6082-T6 butt-joints in bobbin friction stir welding were evaluated using a set of developed reagents and optical microscopy. The key findings are that the dark curved patterns (conventionally called 'flow-arms'), are actually oxidation layers at the advancing side, and at the retreating side are elongated grains with a high-density of accumulation of sub-grain boundaries due to dynamic recrystallization. A model of discontinuous flow within the weld is proposed, based on the microscopic observations. It is inferred that the internal flow is characterized by packets of material ('flow patches') being transported around the pin. At the retreating side they experience high localized shearing at their mutual boundaries, as evidenced in high density of sub-grain boundaries. Flow patches at the advancing side are stacked on each other and exposed to oxidization. View Full-Text
Keywords: bobbin friction stir welding; materials flow; metallography; AA6082-T6; weld defect bobbin friction stir welding; materials flow; metallography; AA6082-T6; weld defect
Show Figures

Graphical abstract

MDPI and ACS Style

Tamadon, A.; Pons, D.J.; Clucas, D.; Sued, K. Internal Material Flow Layers in AA6082-T6 Butt-Joints during Bobbin Friction Stir Welding. Metals 2019, 9, 1059.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop